This invention is concerned generally with printed circuit assemblies, and more specifically with repair of printed circuit assemblies.
Often, circuit boards or assemblies have systematic defects, such as when the boards or assemblies are not designed or manufactured correctly. Incorrectly designed boards or assemblies may contain undesirable short circuits, open circuits or misrouted traces. It is normal industry practice to install jumper wires and have traces cut as appropriate to correct the defects in the boards or assemblies. If the boards or assemblies are low cost or if repair of the boards or assemblies proves to be too difficult, the boards are often scrapped and replaced. However, when the boards or assemblies are expensive or other circumstances exist that prevent scrapping, the boards or assemblies need to be repaired. When repair is required for a defective group of boards or assemblies, there are often hundreds or thousands of boards needing attention. In such circumstances, it is advantageous to have the repair process and mechanisms as simple, repeatable and robust as possible. This is especially true if the repair is difficult, such as rerouting electrical signals under a ball grid array (BGA) component.